There exist today, of course, many burners belonging to this category.
However, various practical difficulties remain linked in particular to problems of excessive heating in the flame holding zones, of flame instability and of combustion quality, liable to generate malfunctions and in particular excessive production of carbon monoxide, or even damage to burners.
In particular, in the context of the immersed tube installations designed for the heating of industrial baths, the applicant has already proposed some solutions, one of which is set forth in French Patent Application FR-A-2,606,492 filed on 7 Nov. 1986.